mm/slub: introduce __kmem_cache_free_bulk() without free hooks

Currently, when __kmem_cache_alloc_bulk() fails, it frees back the
objects that were allocated before the failure, using
kmem_cache_free_bulk(). Because kmem_cache_free_bulk() calls the free
hooks (kasan etc.) and those expect objects processed by the post alloc
hooks, slab_post_alloc_hook() is called before kmem_cache_free_bulk().

This is wasteful, although not a big concern in practice for the very
rare error path. But in order to efficiently handle percpu array batch
refill and free in the following patch, we will also need a variant of
kmem_cache_free_bulk() that avoids the free hooks. So introduce it first
and use it in the error path too.

As a consequence, __kmem_cache_alloc_bulk() no longer needs the objcg
parameter, remove it.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index f0cd55bb4e11a4d7756fcf005c8f582bf5d19232..16748aeada8fe3a424ccfa093ce702773c4c4450 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3919,6 +3919,27 @@ int build_detached_freelist(struct kmem_cache *s, size_t size,
        return same;
 }
 
+/*
+ * Internal bulk free of objects that were not initialised by the post alloc
+ * hooks and thus should not be processed by the free hooks
+ */
+static void __kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
+{
+       if (!size)
+               return;
+
+       do {
+               struct detached_freelist df;
+
+               size = build_detached_freelist(s, size, p, &df);
+               if (!df.slab)
+                       continue;
+
+               do_slab_free(df.s, df.slab, df.freelist, df.tail, df.cnt,
+                            _RET_IP_);
+       } while (likely(size));
+}
+
 /* Note that interrupts must be enabled when calling this function. */
 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 {
@@ -3940,7 +3961,7 @@ EXPORT_SYMBOL(kmem_cache_free_bulk);
 
 #ifndef CONFIG_SLUB_TINY
 static inline int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
-                       size_t size, void **p, struct obj_cgroup *objcg)
+                                         size_t size, void **p)
 {
        struct kmem_cache_cpu *c;
        unsigned long irqflags;
@@ -4004,14 +4025,13 @@ static inline int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
 
 error:
        slub_put_cpu_ptr(s->cpu_slab);
-       slab_post_alloc_hook(s, objcg, flags, i, p, false, s->object_size);
-       kmem_cache_free_bulk(s, i, p);
+       __kmem_cache_free_bulk(s, i, p);
        return 0;
 
 }
 #else /* CONFIG_SLUB_TINY */
 static int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
-                       size_t size, void **p, struct obj_cgroup *objcg)
+                                  size_t size, void **p)
 {
        int i;
 
@@ -4034,8 +4054,7 @@ static int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
        return i;
 
 error:
-       slab_post_alloc_hook(s, objcg, flags, i, p, false, s->object_size);
-       kmem_cache_free_bulk(s, i, p);
+       __kmem_cache_free_bulk(s, i, p);
        return 0;
 }
 #endif /* CONFIG_SLUB_TINY */
@@ -4055,7 +4074,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
        if (unlikely(!s))
                return 0;
 
-       i = __kmem_cache_alloc_bulk(s, flags, size, p, objcg);
+       i = __kmem_cache_alloc_bulk(s, flags, size, p);
 
        /*
         * memcg and kmem_cache debug support and memory initialization.